Black Staz-On Pad won't accept ink

[speedsk8ter]

I have about 5 Black Staz-On ink pads that I used to use when I was teaching classes. Now it seems that none of them will accept ink when I try to re-ink them. It's almost as if there is a hard film on the pads. If I do get enough ink in them to stamp, it seems as if once I stamp a few images, it's out of ink again. Do I just need to bite the bullett and buy new pads? They did get a lot of hard use in my classes. Just curious if anyone else has experienced this? Thanks!

[mycraftyideas]

I have the same problem when I tried to reink my black Stazon. My guess is that I left it too dry before I bought my reinker. The topmost ink may have dried and formed the layer of film.